EFFICIENTLY DELIVERING ACOUSTIC STIMULATION ENERGY TO TISSUE

• US 20140107725A1
• Filed: 12/20/2013
• Published: 04/17/2014
• Est. Priority Date: 08/01/2005
• Status: Active Grant

• Current Assignee: EBR Systems, Inc.
• Original Assignee: EBR Systems, Inc.
• Inventors: Cowan, Mark A.
• Granted Patent: US 9,014,803 B2
• Time in Patent Office: Days
• US Class Current: 607/30
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.

Claims

1. A method for driving an implanted acoustically powered receiver-stimulator having at least one tissue-engaging electrode with a tissue-electrode impedance, said method comprising:

directing an acoustic transmission towards the implanted receiver-stimulator, said transmission having an envelope selected to compensate for the tissue-electrode impedance.

2. A method as in claim 1, wherein said transmission has a decreasing amplitude.

3. A method as in claim 2, wherein said transmission has an exponentially decreasing amplitude.

4. A method as in claim 2, wherein the amplitude has an initial and final value and the final amplitude of the transmission is from 40% to 60% of the initial amplitude.

5. A method as in claim 1, wherein said transmission has an envelope of arbitrary shape.

6. A method as in any of claims 1, wherein directing the acoustic transmission is generated by supplying voltage to an acoustic transmitter amplifier and controlling the supplied voltage to produce an acoustic transmission having a pre-selected envelope.

7. A method as in claim 6, wherein the supplied voltage is controlled by selecting the capacitance of an energy storage capacitor in a transmitter voltage power supply circuit.

8. A method as in claim 1, wherein the acoustic transmission is generated by an implanted controller-transmitter.

9. A method as in claim 1, wherein the acoustic transmission is generated by an external controller-transmitter.

10. A method for delivering an electrical stimulation pulse to tissue, said method comprising:

directing an acoustic transmission having an envelope and is powered by circuitry including an energy storage capacitor;

implanting a receiver-stimulator having circuitry including an envelope detector to produce an electrical stimulation pulse having a voltage proportional to the amplitude of the envelope of the acoustic transmission; and

delivering the electrical stimulation pulse to tissue using electrodes having a tissue-electrode impedance;

wherein the capacitance of the energy storage capacitor is selected to produce an acoustic transmission with an envelope of decreasing amplitude.

11. A method as in claim 10, wherein the stimulation pulse is delivered to cardiac tissue to effect pacing.

12. A method as in claim 11, wherein the acoustic transmission has an envelope selected to compensate for the tissue-electrode impedance.

13. A method as in claim 10, wherein the acoustic transmission is generated by an implanted controller-transmitter.

14. A method as in claim 10, wherein the acoustic transmission is generated by an external controller-transmitter.

15. A system for delivering an electrical stimulation pulse to tissue, said system comprising:

a controller-transmitter having circuitry which produces an acoustic transmission waveform having an envelope and includes an energy storage capacitor; and

a receiver-stimulator having a circuitry which includes an envelope detector which receives the acoustic transmission and produces an electrical stimulation pulse having a voltage proportional to the amplitude of the acoustic transmission envelope;

wherein the capacitance of the energy storage capacitor is selected to produce an acoustic transmission with an envelope of decreasing amplitude.

16. A system as in claim 15, wherein the receiver-stimulator is adapted to deliver a stimulation pulse to cardiac tissue to effect pacing.

17. A system as in claim 16, wherein the acoustic transmission has an envelope selected to compensate for the tissue-electrode impedance.

18. A system as in any of claims 15, wherein the controller-transmitter is implanted.

19. A system as in any of claims 15, wherein the controller-transmitter is external.